To maximize the performance of the next generation of vehicles, including hybrid electric vehicles (HEV), the Army needs an integrated design tool. Employing the latest advances in computer conceptual design and simulation techniques, ThermoAnalytics, Inc.(TAI) proposes to create a tool to allow designers to simultaneously optimize drivetrain performance, thermal management, and signature control. TAI will integrate two of their software packages: HEVSIM, a HEV design and simulation package, and MuSES, apowerful thermal analysis and signature prediction tool. TAI will also add in new and innovative modules. To design cooling and exhaust systems, TAI will develop a fluid flow analyzer. This CFD code will be tailored to these specific flow problems, thusallowing the code to be tuned for fast and easy use. To solve for volumetric heat transfer in thick armor blocks, TAI will use the boundary element method (BEM). Compared with conventional finite element techniques, BEM is faster and more tolerant of meshimperfections. Overall, the GUI-based vehicle design tool will provide continuous performance feedback to the user throughout the design process, guiding the user through parameter trades and design space explorations. The end result will be robust vehicledesigns optimized for performance, efficiency, and survivability.The proposed engineering tool can be applied to the design of both new vehicles and retrofits of existing vehicles. The tool can be used for vehicle subsystem design, infrared signatureprediction, and to analyze the impacts of material and coating degradation. With its ability to model the whole environment and its impact on vehicle performance, the tool can assess how a vehicle will perform under differing climates and weather. Thetechniques developed for rapid simulation of the thermal vegetation background can be applied to real-time simulators. The mobility module can be used to assess vehicle mobility for various terrains and conditions. Additional military benefits includesignature reduction due to coating suppression (camouflage and BRDF tools), shaping (Eclectic), exhaust suppression (1D and 3D fluid codes), and mission analysis for advanced powertrains such as HEV (silent mode, length of mission, power for weapons vs.mobility).